<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div class="main">
       <button id="addData">添加一条数据</button>
        <ul>
            <li>Hello</li>
        </ul>
    </div>
</body>
</html>